TRANSFORMER 50 KvA

[Led Lolly Yellow Lolly]

These three phase conductors are all hooked up to phase 1.

I don't want to scare you but I wouldn't want to use your pool. Proper electricals with swimming pool equipotential safe zoning is a whole area of expertise in and of itself!

 

This system is clearly a mess. It was probably fine when installed but it's been hacked up later by idiots. The more I look at it the more I despair about the way things are here.

 

[Led Lolly Yellow Lolly]

I also just realised that surge protection doesn't look like it's rated for use as a primary surge arrestor. Please take clearer pictures.

[JAN]

[Led Lolly Yellow Lolly]

Can you take a pic of the transformer up on the pole and any switchgear around it? Do you know if this panel goes directly to it?

[JAN]

These are picts of the main breaker 80 Amp and the surge protector unit installed.

 

The small grey wires from the main breaker are gong to the orange unit, also some protector unit.

 

This meter is e secondary one. The one that is usually read is near the transformer mast.

 

 

[JAN]

Indeed, I think I need a professional to sort it out. This is serious freaking me out:)  I am in Chiang Mai; anybody can recommend somebody?

 

[ding]

I'd need to know voltage and load of everything. I think Thailand uses 220V for calcs, no? The breaker can take 440V, is that your primary side?

 

But here's a Schneider Electric xfmr sizing tool online that shows ampacities of 108 Amps at 240V ...or 125 Amps at 208V - 3 phase, 45KVA xfmr;

https://tools.se.app/transformerdata/index.html?language=en&country=usa#/transformer-data

 

Transformers transform one voltage to a different voltage depending on the winding ratios of 2 "coils" with an air gap between that a voltage is induced across. Usually need to know the primary and secondary voltages too.

 

Then there's 'available fault current' ... the fun never stops.

[Crossy]

29 minutes ago, JAN said:

The small grey wires from the main breaker are gong to the orange unit, also some protector unit.

 

Can you post a photo of the "some protector unit" please?

 

I'll lay odds that it's these devices that are causing the MCCB to operate.

[ding]

2 hours ago, Led Lolly Yellow Lolly said:

NE bond also appears to be missing 

 

 

 

 

 

 

Could you tell me what "NE" stands for? Many countries use different terms. Is that the neutral bond?

 

I'm used to grounded systems and this is foreign to me.

 

I can't tell from the pics if this needs a Main Bonding Jumper or should be floated from the Neutral after the main. What he needs is a line diagram and to specify available voltages, load demands, ampacities of breakers and equipment - and wire sizes. Then we can start to help.

[Crossy]

Just now, ding said:

Could you tell me what "NE" stands for? Many countries use different terms. Is that the neutral bond?

 

Neutral-Earth bond. 

 

Thailand is (mostly) 3-phase, 4-wire, 380V ph-ph (220V ph-N) supplied as TNC-S with MEN (multiple earthed neutral) implemented as a grounding rod to the neutral on every 3rd pole.

[JAN]

 

 

 

 

 

 

The small grey wires from the main breaker (seen on the left of breaker) are going to this orange box, on the top left,with the "ON" sign on.

[JAN]

 

[Crossy]

14 minutes ago, JAN said:

The small grey wires from the main breaker (seen on the left of breaker) are going to this orange box, on the top left,with the "ON" sign on.

 

Just there?

 

That's your lost phase / under voltage / over voltage unit - do you have the instructions you may be able to make it less enthusiastic?

 

Do you have any actual 3-phase equipment?

[JAN]

[JAN]

Some pictures of the transformer, it's fuses, PEA meter, etc. After this the wires go straight to the breaker unit.

 

[Led Lolly Yellow Lolly]

You have some blade fuses and surge arresters under the transformer. If I was going to be picky, the crossbar with those fuses is mounted way too low. It's common here to see them so low you can reach out and touch them.

FWIW the first line of defense against lightning is those arcing horns on the ceramic insulators on the transformer. Second line of defense is the surge arresters where those blade fuses are. Third line of defense is the MOVs in your indoor panel.

 

 

 

[JAN]

That's your lost phase / under voltage / over voltage unit - do you have the instructions you may be able to make it less enthusiastic?

 

Do you have any actual 3-phase equipment?

 

 

 

The OV/UV unit was all set at 15. I changed all of them, the OV, UV and UB to 18 now. Times I left at "5"

 

3 phase equipment are the well water pump, sprinkler and pool pumps.

[Led Lolly Yellow Lolly]

3 phase motors are always the logical choice if you have 3 phase power available, no start capacitor to keep failing.

[Led Lolly Yellow Lolly]

5 minutes ago, JAN said:

Times I left at "5"

 

 

This is almost certainly your tripping problem (in isolation from all the other problems mentioned in this thread). Personally I think it's poor design to have one of these phase guards tripping a manual reset breaker, particularly where the power is as flakey as it is in Thailand.

 

 

 

 

 

 

 

[JAN]

This (5) is the maximum value. Would you recommend to isolate it/remove this unit?

[Led Lolly Yellow Lolly]

It shouldn't be on the front end like that. You put phase protection at the point the protected equipment is with a contactor system (which will self-recover) e.g. at the pool pumps. Instead you have the cheap and nasty option (and VERY inconvenient!)

[Crossy]

2 hours ago, JAN said:

This (5) is the maximum value. Would you recommend to isolate it/remove this unit?

 

I would, but you would need to add phase loss protection at the appliances as noted by @Led Lolly Yellow Lolly

[JAN]

If I remove this particular orange box, which I think is the phase loss protection unit, then I would have to add to each of the 3 phase appliances, pumps, etc. one orange box. Isn't it?

[Crossy]

36 minutes ago, JAN said:

If I remove this particular orange box, which I think is the phase loss protection unit, then I would have to add to each of the 3 phase appliances, pumps, etc. one orange box. Isn't it?

 

Yes, I'm afraid so, or you could just risk damage to your 3-phase motors.

 

You can get individual units for very sensible numbers on Lazada etc. 

 

Something like this from a very quick search https://www.lazada.co.th/products/sinotimer-stvp-60-3-phase-380v-60a-din-rail-auto-recovery-over-and-under-voltage-protector-industrial-surge-protection-relay-i2352075555-s7946848050.html

[Led Lolly Yellow Lolly]

You might already have phase protection in your pool pump Room. Take pictures. I'll take pictures of my own systems later so you know what to look for.

[Led Lolly Yellow Lolly]

Here is the pump controller in my swimming pool pump room. You can see the phase protector next to the 3 x contactors in the middle. This is where phase protection should be, NOT on the main incomer as is the case at your place. . .

 

 

 

 

 

I'll also post some pics of my main incomer, see also my comments further down. . .

 

 

 

 

 

 

Our business is presently in mothballs due to covid, so the ammeter barely registers anything, but I want to highlight that the ammeter, like yours, would need to be sensing high currents before the needle moves, so that doesn't necessarily mean it's not working. . .

 

Also, please take note of the Perspex screen in front of the coloured bus bars. This exists to protect from accidental contact, for example, a screwdriver falling onto the bus bars creating an arc flash. In your installation, this, along with some of the plastic phase guards on the breakers, is missing. PLEASE be cautious when opening your panel, it really is a dangerous thing you're doing.

 

 

 

 

 

 

 

 

[ding]

On 6/6/2021 at 7:26 PM, Crossy said:

 

Neutral-Earth bond. 

 

Thailand is (mostly) 3-phase, 4-wire, 380V ph-ph (220V ph-N) supplied as TNC-S with MEN (multiple earthed neutral) implemented as a grounding rod to the neutral on every 3rd pole.

Thanks. That's the main bonding jumper (MBJ) in my country; GEC to grounded conductor. Or system bonding jumper (SBJ) in a transformer; X-O to GEC.

Too many strange terms and voltages etc for me to follow along. Thanks for the help here.

[Crossy]

8 minutes ago, ding said:

Too many strange terms and voltages etc for me to follow along. Thanks for the help here.

 

Yeah, there's no global standardisation of terms I'm afraid. 

 

Just think how many different names an RCD gets ???? 

[Led Lolly Yellow Lolly]

The OP went quiet, last visited June 8th. I hope he didn't blow himself up.